module: support pattern trailers

PR-URL: #39635 Reviewed-By: Bradley Farias <[email protected]>

Author: guybedford

doc/api/esm.md

@@ -1169,25 +1169,36 @@ The resolver can throw the following errors:
 **PACKAGE_IMPORTS_EXPORTS_RESOLVE**(_matchKey_, _matchObj_, _packageURL_,
 _isImports_, _conditions_)
 
->1. If _matchKey_ is a key of _matchObj_, and does not end in _"*"_, then
+>1. If _matchKey_ is a key of _matchObj_ and does not end in _"/"_ or contain
+> _"*"_, then
 >1. Let _target_ be the value of _matchObj_\[_matchKey_\].
 >1. Let _resolved_ be the result of**PACKAGE_TARGET_RESOLVE**(
 > _packageURL_, _target_, _""_, **false**, _isImports_, _conditions_).
 >1. Return the object _{resolved, exact:**true** }_.
->1. Let _expansionKeys_ be the list of keys of _matchObj_ ending in _"/"_
-> or _"*"_, sorted by length descending.
+>1. Let _expansionKeys_ be the list of keys of _matchObj_ either ending in
+> _"/"_ or containing only a single _"*"_, sorted by the sorting function
+> **PATTERN_KEY_COMPARE** which orders in descending order of specificity.
 > 1. For each key _expansionKey_ in _expansionKeys_, do
->1. If _expansionKey_ ends in _"*"_ and _matchKey_ starts with but is
-> not equal to the substring of _expansionKey_ excluding the last _"*"_
-> character, then
->1. Let _target_ be the value of _matchObj_\[_expansionKey_\].
->1. Let _subpath_ be the substring of _matchKey_ starting at the
-> index of the length of _expansionKey_ minus one.
->1. Let _resolved_ be the result of**PACKAGE_TARGET_RESOLVE**(
-> _packageURL_, _target_, _subpath_, **true**, _isImports_,
-> _conditions_).
->1. Return the object _{resolved, exact:**true** }_.
->1. If _matchKey_ starts with _expansionKey_, then
+> 1. Let _patternBase_ be **null**.
+> 1. If _expansionKey_ contains _"*"_, set _patternBase_ to the substring of
+> _expansionKey_ up to but excluding the first _"*"_ character.
+> 1. If _patternBase_ is not **null** and _matchKey_ starts with but is not
+> equal to _patternBase_, then
+> 1. Let _patternTrailer_ be the substring of _expansionKey_ from the
+> index after the first _"*"_ character.
+> 1. If _patternTrailer_ has zero length, or if _matchKey_ ends with
+> _patternTrailer_ and the length of _matchKey_ is greater than or
+> equal to the length of _expansionKey_, then
+> 1. Let _target_ be the value of _matchObj_\[_expansionKey_\].
+> 1. Let _subpath_ be the substring of _matchKey_ starting at the
+> index of the length of _patternBase_ up to the length of
+> _matchKey_ minus the length of _patternTrailer_.
+> 1. Let _resolved_ be the result of **PACKAGE_TARGET_RESOLVE**(
+>_packageURL_, _target_, _subpath_, **true**, _isImports_,
+>_conditions_).
+> 1. Return the object _{resolved, exact:**true** }_.
+>1. Otherwise if _patternBase_ is **null** and _matchKey_ starts with
+> _expansionKey_, then
 >1. Let _target_ be the value of _matchObj_\[_expansionKey_\].
 >1. Let _subpath_ be the substring of _matchKey_ starting at the
 > index of the length of _expansionKey_.
@@ -1197,6 +1208,22 @@ _isImports_, _conditions_)
 >1. Return the object _{resolved, exact:**false** }_.
 >1. Return the object _{resolved:**null**, exact:**true** }_.
 
+**PATTERN_KEY_COMPARE**(_keyA_, _keyB_)
+
+>1. Assert: _keyA_ ends with _"/"_ or contains only a single _"*"_.
+>1. Assert: _keyB_ ends with _"/"_ or contains only a single _"*"_.
+>1. Let _baseLengthA_ be the index of _"*"_ in _keyA_ plus one, if _keyA_
+> contains _"*"_, or the length of _keyA_ otherwise.
+>1. Let _baseLengthB_ be the index of _"*"_ in _keyB_ plus one, if _keyB_
+> contains _"*"_, or the length of _keyB_ otherwise.
+>1. If _baseLengthA_ is greater than _baseLengthB_, return-1.
+>1. If _baseLengthB_ is greater than _baseLengthA_, return1.
+>1. If _keyA_ does not contain _"*"_, return1.
+>1. If _keyB_ does not contain _"*"_, return-1.
+>1. If the length of _keyA_ is greater than the length of _keyB_, return-1.
+>1. If the length of _keyB_ is greater than the length of _keyA_, return1.
+>1. Return 0.
+
 **PACKAGE_TARGET_RESOLVE**(_packageURL_, _target_, _subpath_, _pattern_,
 _internal_, _conditions_)
 

doc/api/packages.md

@@ -360,9 +360,8 @@ For these use cases, subpath export patterns can be used instead:
 **`*` maps expose nested subpaths as it is a string replacement syntax
 only.**
 
-The left hand matching pattern must always end in `*`. All instances of `*` on
-the right hand side will then be replaced with this value, including if it
-contains any `/` separators.
+All instances of `*` on the right hand side will then be replaced with this
+value, including if it contains any `/` separators.
 
 ```js
 importfeatureXfrom'es-module-package/features/x';

lib/internal/modules/esm/resolve.js

@@ -15,7 +15,9 @@ const{
  SafeSet,
  String,
  StringPrototypeEndsWith,
+ StringPrototypeIncludes,
  StringPrototypeIndexOf,
+ StringPrototypeLastIndexOf,
  StringPrototypeReplace,
  StringPrototypeSlice,
  StringPrototypeSplit,
@@ -502,7 +504,9 @@ function packageExportsResolve(
 if(isConditionalExportsMainSugar(exports,packageJSONUrl,base))
 exports={'.': exports};
 
-if(ObjectPrototypeHasOwnProperty(exports,packageSubpath)){
+if(ObjectPrototypeHasOwnProperty(exports,packageSubpath)&&
+!StringPrototypeIncludes(packageSubpath,'*')&&
+!StringPrototypeEndsWith(packageSubpath,'/')){
 consttarget=exports[packageSubpath];
 constresolved=resolvePackageTarget(
 packageJSONUrl,target,'',packageSubpath,base,false,false,conditions
@@ -513,30 +517,38 @@ function packageExportsResolve(
 }
 
 letbestMatch='';
+letbestMatchSubpath;
 constkeys=ObjectGetOwnPropertyNames(exports);
 for(leti=0;i<keys.length;i++){
 constkey=keys[i];
-if(key[key.length-1]==='*'&&
+constpatternIndex=StringPrototypeIndexOf(key,'*');
+if(patternIndex!==-1&&
 StringPrototypeStartsWith(packageSubpath,
-StringPrototypeSlice(key,0,-1))&&
-packageSubpath.length>=key.length&&
-key.length>bestMatch.length){
-bestMatch=key;
+StringPrototypeSlice(key,0,patternIndex))){
+constpatternTrailer=StringPrototypeSlice(key,patternIndex+1);
+if(packageSubpath.length>=key.length&&
+StringPrototypeEndsWith(packageSubpath,patternTrailer)&&
+patternKeyCompare(bestMatch,key)===1&&
+StringPrototypeLastIndexOf(key,'*')===patternIndex){
+bestMatch=key;
+bestMatchSubpath=StringPrototypeSlice(
+packageSubpath,patternIndex,
+packageSubpath.length-patternTrailer.length);
+}
 }elseif(key[key.length-1]==='/'&&
 StringPrototypeStartsWith(packageSubpath,key)&&
-key.length>bestMatch.length){
+patternKeyCompare(bestMatch,key)===1){
 bestMatch=key;
+bestMatchSubpath=StringPrototypeSlice(packageSubpath,key.length);
 }
 }
 
 if(bestMatch){
 consttarget=exports[bestMatch];
-constpattern=bestMatch[bestMatch.length-1]==='*';
-constsubpath=StringPrototypeSubstr(packageSubpath,bestMatch.length-
-(pattern ? 1 : 0));
-constresolved=resolvePackageTarget(packageJSONUrl,target,subpath,
-bestMatch,base,pattern,false,
-conditions);
+constpattern=StringPrototypeIncludes(bestMatch,'*');
+constresolved=resolvePackageTarget(packageJSONUrl,target,
+bestMatchSubpath,bestMatch,base,
+pattern,false,conditions);
 if(resolved===null||resolved===undefined)
 throwExportsNotFound(packageSubpath,packageJSONUrl,base);
 return{ resolved,exact: pattern};
@@ -545,6 +557,20 @@ function packageExportsResolve(
 throwExportsNotFound(packageSubpath,packageJSONUrl,base);
 }
 
+functionpatternKeyCompare(a,b){
+constaPatternIndex=StringPrototypeIndexOf(a,'*');
+constbPatternIndex=StringPrototypeIndexOf(b,'*');
+constbaseLenA=aPatternIndex===-1 ? a.length : aPatternIndex+1;
+constbaseLenB=bPatternIndex===-1 ? b.length : bPatternIndex+1;
+if(baseLenA>baseLenB)return-1;
+if(baseLenB>baseLenA)return1;
+if(aPatternIndex===-1)return1;
+if(bPatternIndex===-1)return-1;
+if(a.length>b.length)return-1;
+if(b.length>a.length)return1;
+return0;
+}
+
 functionpackageImportsResolve(name,base,conditions){
 if(name==='#'||StringPrototypeStartsWith(name,'#/')){
 constreason='is not a valid internal imports specifier name';

test/es-module/test-esm-exports.mjs

@@ -35,7 +35,12 @@ import fromInside from '../fixtures/node_modules/pkgexports/lib/hole.js'
 ['pkgexports-sugar',{default: 'main'}],
 // Path patterns
 ['pkgexports/subpath/sub-dir1',{default: 'main'}],
+['pkgexports/subpath/sub-dir1.js',{default: 'main'}],
 ['pkgexports/features/dir1',{default: 'main'}],
+['pkgexports/dir1/dir1/trailer',{default: 'main'}],
+['pkgexports/dir2/dir2/trailer',{default: 'index'}],
+['pkgexports/a/dir1/dir1',{default: 'main'}],
+['pkgexports/a/b/dir1/dir1',{default: 'main'}],
 ]);
 
 if(isRequire){
@@ -77,6 +82,8 @@ import fromInside from '../fixtures/node_modules/pkgexports/lib/hole.js'
 ['pkgexports/null/subpath','./null/subpath'],
 // Empty fallback
 ['pkgexports/nofallback1','./nofallback1'],
+// Non pattern matches
+['pkgexports/trailer','./trailer'],
 ]);
 
 constinvalidExports=newMap([
@@ -147,6 +154,8 @@ import fromInside from '../fixtures/node_modules/pkgexports/lib/hole.js'
 ['pkgexports/sub/not-a-file.js',`pkgexports${sep}not-a-file.js`],
 // No extension lookups
 ['pkgexports/no-ext',`pkgexports${sep}asdf`],
+// Pattern specificity
+['pkgexports/dir2/trailer',`subpath${sep}dir2.js`],
 ]);
 
 if(!isRequire){